… allow configuring + disabling of the fade effect (#339)

* Support a fade=false prop in the Modal component

- if fade=false, the following happens:
  - no 'fade' class is applied
  - the modal + backdrop transition timeouts become 0
  - the transitionAppear, etc. booleans passed to Fade are false

* Update fadeless-modal to not use the Fade component

- This feels like a better design. If we are not doing
  a fade effect, why use a Fade component?
- This also gets rid of the usage of TransitionGroup
  when fade={false}.
- Ensure onEnter and onExit fire when expected.

* DRY up shared code between fade-modal and fadeless-modal

- Extract modalDialog rendering into a separate method
- Simplify the variable setting in #renderChildren
  following the movement of several of them into
  #modalDialog

* Make modalTransitionTimeout and backdropTransitionTimeout configurable as props

- Update docs
- Add test

* Fix warning about missing context in DropdownMenu spec

* Allow configuring appear v. enter v. leave timeouts separately

A new linter rule lines up with new browser spec prohibits a trailing comma after the rest syntax.
Since there can be no variables defined after the rest, it is pointless to have a comma dangle there.

This updates enzyme to remove the depractation Warning: ReactTestUtils has been moved to react-dom/test-utils. Update references to remove this warning.
keeping addon test utils for backwards compatibility until the min react version for this project is updated. Enzyme will use it if needed.

…umentation pages. (#381)

* docs(Utilities): add utilities and color page

* doce(Clearfix): add clearfix page in utilities

Using the PropTypes via the react package is deprecated as of React
15.5.0.

Use the PropTypes from the prop-types package as recommended.

See https://facebook.github.io/react/blog/2017/04/07/react-v15.5.0.html

…#399)

* fix(Modal): Made focus optional

* set default focus to true

* rename prop to autoFocus

…ng in class (#410)

Example:
initial body class: `no-modal-opened`
open and close modal, body class: `no-ed modal-open`

* fix(ButtonDropdown) group={false} did nothing

The underlying Object.assign needs to have the overrides to the right it seems like

```function example(){
  let props = {group: "FROM PROPERTIES" };
  let propsOverwritten = Object.assign({}, props, {'group': "group from defaults"});
  console.log("props first, groups overwritten", propsOverwritten);
  
  let notOverwritten = Object.assign({}, {'group': "group from defaults"}, props);
  console.log("groups first, overwritten by props as intended", notOverwritten);
}


example()
```

ES6 example https://es6console.com/j2paoelc/

Not crazy sure, but I changed the order in `reactstrap.es.js` of `g,{group:!0}` and it worked, so this seems like it would have the appropriate affect.

* fix extra space

* add space to fix lint rule